Grinding paste



Patented Nov. 24, 1925.

UNITED STATES PATRICK HOLMSTROM, OF HEMET, CALIFORNIA.

GRINDING PASTE.

No Drawing.

T 0 all whom it may concern:

Be it known that I, PATRICK I'IOLMSTROM, a citizen of the United States, residing at Hemet, in the county of Riverside and State of California, have invented a new and useful Grinding Paste, of which the following is a specification.

This invention relates to a composition of matter, that is to say, an abrasive substance or a. grinding paste intended to be used between two rubbing faces which must work together in the operation of a machine, for example, the paste is intended to be used in grinding valves on their seats; also in lapping pistons. lVhile the invention relates to the composition of the grinding paste, it also resides in the novel method or mode of operation of the pastewhen used for grinding a valve.

The general object of this invention is to provide a composition which will operate as an effective grinding paste and which has properties of cohesion and adhesion which will enable it to maintain itself distributed between the rubbing faces.

Before proceeding to adetailed descrip tion of this composition and its mode of operation in use, I shall refer to the manner in which valves are usually ground in practice. In this operation the disc of the valve is placed on its seat and the stem of the valve is then rotated first in. one direction and then in the other, and while this takes place the valve is auton'iatically raised from its seat and then returned to the seat. Abrasive substances or pastes have been used between the rubbing faces butthere is av tendency for these substances to be rubbed away so that they do not maintain an effective grinding film between the rubbing faces, uniformly distributed.

In practicing my invention, I provide a substance which is effective in its abrasive properties and which is very highly cohesive and adhesive, so that when the valve is raised slightly from its seat as referred to above, a

Application filed. October 11, 1923. Serial No. 667,806.

film of the abrasive stretches itself between the seat and the face of the valve. When the valve returns to its seat, this film is spread between the rubbing faces. In this way the regular operation of periodically lifting the valve from its seat is instrumental in assisting in making a redistribution of the paste between the rubbing faces.

The composition which I prefer to employ includes as an ingredient citrus powder and an abrasive substance, for example, finely divided carborundum; these substances are mixed with a small quantity of liquid.

In preparing this paste I mix about a teaspoonful of citrus powder with about a tablespoonful of boiling water. This: 1nixture is then stirred and will form itself into a cheesy paste. Into this paste I mix the carbornnduln powder and stir until it is evenly distributed throughout the paste.

In grinding a valve I simply smear small quantities of this paste on the face of the valve or on the valve seat and then grind the valve in the usual way.

In this way I make use of the high cohesive and adhesive properties of this mixture to assist in maintaining a grinding film upon the rubbing faces. The substance may also be used for lapping a. piston in a cylinder.

It is understood that the embodiment of the invention described herein is only one of the many embodiments this invention may take and I do not wish to be limited in the practice of my invention nor in my claims to the particular embodiment set forth.

lVhat I claim is:

1. As a. new composition of matter, a grinding paste containing citrus powder, a liquid, and an abrasive powder.

2. As a new composition of matter, a grinding paste containing citrus powder, a liquid, and powdered carborundum.

Signed at Los Angeles, California, this 41th day of October, 1923.

PATRICK IIOLMSTROM. 

